1. Field of the Invention
The present invention relates to a condition determining system capable of determining a condition of a target instrument, such as an image forming apparatus, using a condition determining apparatus by connecting the condition determining apparatus with the target instrument to execute communications therebetween via a communication network, a method of detecting abnormality of such a system, and an image forming apparatus.
2. Discussion of the Background Art
It is described in the Japanese Patent Application Laid Open No. 8-195849 that in a control apparatus connected to a communication network with a target instrument, condition information transmitted from the target instrument is analyzed so as to expedite maintenance for the target instrument. Specifically, a condition determining system is disclosed in which plural image forming apparatuses calculate times of sheet jam occurrence, and when a provability of frequency of jam occurrence increases, jam alarm information (i.e., condition information) indicating such a condition is transmitted to the control apparatus. In such a system, the control apparatus accumulates the alarm information transmitted from each of the image forming apparatuses, determines tendency thereof, and recognizes an abnormal condition in which a service person needs to visit when the tendency matches with a prescribed pattern. Then, the control apparatus transmits such abnormality information to a terminal installed in a service basis in charge of the image forming apparatus.
However, in a conventional condition determining system, it is unknown if condition information from the instrument is correctly handled from when the instrument is installed and is set up at a user site to ordinarily operate to when the instrument practically transmits the condition information to the control apparatus so that the control apparatus recognizes the abnormality. Further, in a conventional condition determining system, a test as to if a transmission of condition information from a target instrument is in deed possible before installation thereof. However, the test can only confirm feasibility of the transmission, and cannot confirm as to if the control apparatus appropriately practically deals with abnormal information when transmitted.